3-heterocyclicthiomethylcephalosporins

ABSTRACT

Cephalosporins containing a heterocyclicthiomethyl group at position 3 are prepared. The heterocyclic group is 5-oxo- Delta 2-1,2,4-triazolinyl, 5-thiono- Delta 2-1,2,4-triazolinyl, 5-oxoDelta 2-1,2,4-thiadiazolinyl or 5-thiono- Delta 2-1,3,4thiadiazolinyl. The compounds have antibacterial activity.

United States Patent 1 [111 3,868,369 Berge's Feb. 25, 1975 [54]3-HETEROCYCLICTHIOMETHYLCEPH- 3,776,906 l2/l973 Essery et al.... 260/243C ALOSPORINS 3,780,032 l2/l973 Essery et al. 260/243 C [75] Inventor:David Alan Berges, Audubon, Pa.

[73] Assignee: SmithKline Corporation,

Philadelphia, Pa.

[22] Filed: Nov. 14, 1972 [21] Appl. No.: 306,507

[52] U.S. Cl. 260/243 C, 424/246 [51] Int. Cl C07d 99/24 [58] Field ofSearch 260/243 C [56] References Cited UNITED STATES PATENTS 3,766,17610/1973 Lemieux et al. 260/243 C Primary ExaminerNicholas S. RizzoAttorney, Agent, or Firm-Stuart R. Suter; Alan D. Lourie; William H.Edgerton [57] ABSTRACT Cephalosporins containing aheterocyclicthiomethyl 10 Claims, No Drawings3-HETEROCYCLICTHIOMETHYLCEPHALOSPO- ,K JSV This invention relates tonovel cephalosporin compounds that have improved properties. Thesecompounds have antibacterial activity.

The compounds within the scope of the invention are represented by thestructural formula COOH where g X is H, CH OH, SH, or OR;

Y is NH or OH; Z is NR or S;

A is O or S; and

R is hydrogen or C -C alkyl.

Preferred compounds are those having a phenylglycine or mandelic acidsubstituted at position 7, both of which may be unsubstituted orsubstituted with a phydroxy group. Preferred heterocyclic systems atposition 3 are those where Z is nitrogen and A is oxygen, Z is nitrogenand A is sulfur, and Z and A are both sulfur.

Cephalosporins with many and varied substituents are known in the priorart. As related to this invention, cephalosporins that come within thefollowing general formula are described in several patents In particularU.S. Pat. No. 3,641,021 discloses compounds where Acyl isa-aminophenylaeetyl or mandeloyl and Het is thiadiazolyl and tetrazolyl.In Belgian Pat. No. 776,222, Acyl is a-aminophenylacetyl and mandeloyland Het is 1,2,4-triazolyl or other heterocyclic systems. U.S. Pat. No.3,687,948 and Belgian Pat. No. 778,207 claim compounds where Acyl isa-aminophenylacetyl and Het is oxazolyl or 1,2,3-triazolyl,respectively. Compounds where Acyl can be any of variousheterocyclicacetyl systems and Het is 1,2,4- triazolyl,1,3,4-thiadiazolyl or numerous other heterocyclic systems are disclosedin U.S. Pat. No. 3,516,997 and 3,530,123. In all the above prior art,however, the oxo or thiono substituent is not present on any of theheterocyclic systems. U.S. Pat. No. 3,278,531 broadly disclosescephalosporins with many types of substituents at 7 and numeroussulfur-containing groups, both cyclic and acylic, at 3. Within thispatent is a mercaptohydantoin, a group that distinctly differs from theoxoheterocyclic systems of this invention and for which the prior artcompounds that do not have these substituents. For example,7-(a-aminophenylacetamido)-3- (5-oxo-A -l,2,4-triazolin-3-ylthiomethyl)-3-cephem-4- carboxylic acid is morestable in solution at neutral or basic pH than any prior art compoundsthat were tested. Also, the compound has greater stability to copper ionthan tested prior art compounds.

Compounds of this invention are prepared from 7-aminocephalosporanicacid (7-ACA) by standard methods well known in the art. The acctoxygroup of 7-ACA is displaced with the appropriate heterocyclicthionecompound and the 7-amino group is acylated with the phenylglycine ormandelic acid or an activated derivative thereof. The order of these tworeactions is not critical although the usual sequence is displacementfollowed by acylation. With some com-. pounds the reverse order may bepreferred; however. this choice is well within the ability of oneskilled in the art.

The displacement reaction is run in a water; acetone or similar solventsystem at the reflux temperature of the solvent. The solution ismaintained at a pH near neutrality. The product is isolated by standardmethods.

Prior to the acylation, the a-hydroxy and amino groups of the mandelicacid or phenylglycine must be protected with an easily removableprotecting group. Many protecting groups are known and used in the art.for example, dichloroacetyl, tetrahydropyranyl, or tri methylsilyl areused for hydroxy groups and tbutoxycarbonyl, benzyloxy-carbonyl,trichloroethoxycarbonyl, or similar group commonly used in peptidesynthesis are used for amino groups. In addition, prior to acylation,the carboxyl group is activated by its conversion to an activatedderivative such as the acid chloride, mixed anhydride, or an activatingester. If the carboxyl group of the 7-aminocephalosporin is protected.

the acylation may be effected using a coupling reagent such asdicyclohexylcarbodiimide. Following acylation, any protecting groups areremoved in the usual manner.

Starting materials for the product compounds of this invention arecommercially available, prepared by known methods, or described herein.The heterocyclic compounds used in the displacement reaction areprepared by published methods or by variations of known methods thatwould be apparent to one skilled in the art. The preparation ofl,2,4-triazolidin-5-one-3-thione and its 4-alkyl derivatives isdescribed in Chem. Ber., 56, 1370 (1923) and J. Org. Chem., 23, 618(1958). The l-alkyl derivatives are prepared by sodium borohydridereduction of the appropriate thiosemicarbazone to give thel-alkylthiosemicarbazide which is reacted with ethyl chloroformate andthen a strong base. The synthesis of l,2.4-triaZolidin-3,S-dithione isreported in A!Hl.,426, 313 (1921). The l,3,4-thiadiazolidin-5-one-2-thione is prepared analogously to known methods [C/u'm. Ben, 27, 2507(1894)! while the dithione ana log is commercially available.

Optical isomerism will exist in the side chain at position 7 due to thepresence of the assymetrical carbon atom-. while the isomer ispreferred, the L isomer and the racemic mixture are within the scope ofthis invention. In addition, it is recognized that the x0 and thionosubstituents on the heterocyclic group may exist The compounds areadministered for the treatment and prevention of bacterial infections byinjection or oral methods. Methods of formulation and administration arethe same as for other known cephalosporin in othertautomeric forms,i.'e., the hydroxy or mercompounds and are within the skill of the art.c'aptlo'. The compounds may exist exclusively as one Due to the presenceof the acid and amino functions tautorner'or may be in equilibriumbetween the other in thesecompounds, salts can be preparcdby knownforms; however, these are allincluded within the scope methods. Methodsto prepare the acid or base salts or of'this invention. to convertthesalts to the free compound are well The compounds are antibacterialagents with activity known and are obvious to one skilled in the art.The against both Gram-positive and Gram-negative bactenontoxicpharmaceutically acceptable salts of the comria. Minimum inhibitoryconcentrations (MIC) ranged pounds are useful for the same purposes asthe free from 0 1 to greater than '200 ug/ml. Table 1 shows thecompounds and are therefore within the scope of the MlCs against arepresentative group of bacteria for 7- invention.(a-aminophenylacetamide)-3-(5-oxo-A -1,2,4- The following examples arepresented to illustrate triazolin-3-ylthiomethy1)-3-cephem-4-carboxylicacid the invention and are not to be considered limitative. (I),7-(a-aminophenylacetamido)-3-(4-methyl-5-oxo- A-l,2,4-triazolin-3-ylthiomethyl)-3-cephem-4- EXAMPLE 1 carboxylic acid(11), 7-(a-aminophenylacetamido) 3- 7(a-Aminophenylaeetamido)-3-(5-oxo-A-l,2,4- (4-ethy1-5-oxo-A -1,2,4-triazolin-3-y1thiomethyl)-3-triazolin-3-ylthiomethyl)-3-eephem-4-carboxylic acid cephem-4-carboxy1icacid (111), 7-(a-amino-p- In a mixture of water (40 ml) and acetone (10ml) hydroxyphenylacetamido)-3-(5-oxo-A -1 ,2,4-triazo1inwas dissolved7-ACA (2.73 g, 0.01 mol) and NaHCO 3-ylthiomethyl)-3-cephem-4-carboxylicacid (IV), 7- (1.61 g, 0.02 mol) and then l,2,4-triazolidin-5-one-3-mandelamido-3-(5-oxo-A -1,2,4-triazolin-3- thione (1.76 g, 0.015 mol) inacetone (20 ml) was ylthiomethyl)-3-cephem-4-carboxylic acid (V), 7-added. Solid NaHCO was added to adjust the mixturemandelamido-3-(4-methyl-5-oxo-A -1,2,4-triazolin-3- to pH 7 and givecomplete solution. The reaction was ylthiomethyl)-3-cep hem-4-carboxylicacid (VI), and refluxed for 2 hours and then allowed to cool to room7-mandelamido-3-(5-thiono-A -1,3,4-thiadiazolin-2- temperature. Thesolution was cooled with ice. adylthiomethyl)-3-cephem-4-carboxylic acid(Vll). Data justed to pH 3.5 with 3N HCl, and filtered. The colfor knowncephalosporins, cephaloridine (5-1) and lected solid was washed withwater and acetone. and cephalexin (8-11), are included as representativestanthen the solid was dissolved in 3N HCl (15 ml). After dards. In vivostudies in Table 2, giving ED values for filtering, the filtrate wastreated with decolorizing carthe same compounds when administered toinfected bon, filtered, and adjusted to pH 3.5. The solid was colmicesubcutaneously, also show the high activity of lected, washed with waterand acetone, and dried to these compounds. Compounds with thea-amino-pgive the 7-amino-3-(5-oxo-A -1.2,3-triazolin-3-hydr'oxyphenylacetamido group at position 7 have theylthiomethyl)-3-cephem-4-carboxylic acid. special advantage of oralactivity. Compounds IV To a solution of dry THF (92 ml) containingtriethylshowed a ED of 9.5 and 6.2 mg/kg against E.coli and amine (3.2ml, 0.023 ml) was added N-t-butoxycar- Kleb. pneumonia, respectively, ininfected mice when bonylphenylglycine (5.8 g, 0.023 mol). After coolingto the compound was administered orally. 40 10, isobutylchloroformate(3.0 ml, 0.023 mol) was TABLE I U I MIC (pg/m1) Bacteria r 11 111 iv VVI v11 5-1 5-11 S. aureus HH 127 1.6 6.3 3.1 6.3 0.8 1.6 0.8 0.4 3.1 S.aureusSK 23390 1.6 3.1 3.1 6.3 0.4 0.4 0.4 0.1 1.6 Strep. pyog. C203 0.10.1 0.1 0.1 0.1 0.1 0.2 0.1 0.1 Sti'ep. faecalis HH 34358 50 25 50 25 256.3 50 E; coliSK 12140... 3.1. 12.5 12.5 6.3 3.1 6.3 1.6 3.1 6.3 E. COllHH 33779 6.3 25 12.5 25 6.3 12.5 3.1 6.3 6.3 Kleb. pneumo. SK 4200 3.16.3 6.3 6.3 3.1 3.1 1.6 3.1 6.3 Kleb. pneumo; sk 1200 3.1 6.3 6.3 12.51.6 3.1 0.8 3.1 3.1 Pseudomonas sp. HH. 63 200 200 200 200 200 200 200200 200 Sal. paratyphi ATCC 12176 1.6 3.1 3.1 6.3 1.6 3.1 0.8 1.6 3.1Shigparadys. HH 127 3.1 6.3 6.3 12.5 1.6 0.1. 1.6 1.6 6.3 Entcro.aerogencs ATCC13048 6.3 25 25 12.5 12.5 12.5 12.5 200 12.5 Entcro.cloacn P:1.S.l.l%9 12.5 50 25 12.5 200 6.3 Serrantia marcescens 200 200200 200 200 200 200 200 50 ATCC 13880 7 I I Staph. aurcus villaluz 12.525 25 25 25 12.5 12.5 12.5 50

TABLE 2 60 added and the reaction solution was stirred for 30 min-EDmmg/kg) I ute's. A solution of above 7-aminonucleus (7.57 g, CompoundE. C0 SK 12140 K lebj. pneumo. SK 4200 0-023 U n t"mhylamme In 0 P 0aqueous THF"(84 ml) was added over a 25 minute peq riod at .l0. Thereaction was stirred 20 minutes at o a I m 9 93 .5 .40 minutes at 5 and30 minutes at room tempera- Q 4 ture .and 'then'the THF was removed invacuo. The 3 aqueous residue was dilutedwith water ml) and ,v11 21.5 64extracted with ethyl acetate. The water phase was adgj f, ,2 justed topH 3.5 while being cooled, ethyl acetate was added and the mixture wasacidified topH 2.5. A

gummy solid was collected and discarded. The aqueous phase of thefiltrate was separated and extracted with ethyl acetate again. Thecombined extracts were washed with water, dried, and evaporated to afoam to which ether was added and a solid was collected. Acetone wasadded to the product and a solid precipitated from the solution afterstanding 45 minutes. The pure N-protected product was collected anddried.

The above product (5.0 g) was stirred with cold trifluoroacetic acid (50ml) for 45 minutes, the ice bath was removed, and the stirring wascontinued for 45 minutes. The trifluoroacetic acid was evaporated invacuo, and the residue was triturated with ether to give a solid whichwas dissolved in water (50 ml). The aqueous solution was covered withmethyl isobutyl ketone and adjusted to pH 1.9 with tributylamine. Thepure title compound precipitated.

EXAMPLE 2 7-Mandelamido-3-( 5-oxo-A -l ,2,4-triazolin-3-ylthiomethyl)-3-cephem-4-carboxylic acid A solution of the 7-aminonucleus from Example 1 (7.0 g, 0.0213 mol) in a mixture 3% NaHCO 160 ml)and water (160 ml) was cooled to and then O-dichloroacetylmandeloylchloride (12.0 g, 0.0426 mol) was added over a 40 minute period duringwhich time the pH was maintained at 5.5 using 10% NaOH. The reaction wasallowed to warm to 0 over a 30 minute period and was stirred at 0 for 1hour. The solution was filtered, extracted with ether, covered withethyl acetate, adjusted to pH 3, and extracted with ethyl acetate. Theextracts were dried and evaporated to an oil which solidified whentriturated with ether. The solid was dissolved in ethyl acetate andconcentrated to a volume of 30 ml which was added dropwise with stirringto ether (300 ml) to give a solid which was collected and dried. Asolution of the solid in methanol was adjusted to pH 9.6 with a 5percent solution of sodium methoxide in methanol and stirred for 30minutes. 2-Ethylhexanoic acid was added until pH 7 was reached. Thereaction was filtered, diluted with ethyl acetate (150 ml) and filteredagain. The filtrate was concentrated and diluted with more ethyl acetateto give the solid title compound.

EXAMPLE 3 7-(a-Aminophenylacetamido)-3-(4-methy1-5-oxo-A1.2,4-triazolin-3-ylthiomethyl)-3-cephem-4-earboxylic acid 7-ACA (27.23g, 0.1 mol) was suspended in water (200 ml) and acetone (100 ml) andthen a solution of NaHCO (25.2 g. 0.3 mol) in water (200 ml) was added.After heating to 45, 4-methyl-1,2,4-triazolidin- 5-oxo-3-thione (19.67g, 0.15 mol) was added along with additional acetone (200 ml). Thereaction was refluxed for 4 hours during which time the pH wasmaintained at ca. 7.2 by using 3NHC1 as needed. The solution was cooledand adjusted to pH 3.5 which precipitated the product. The7-amino-3-(4-methyl-5-oxo-A1,2,4-triazolin-3-ylthiomethyl)-3-cephem-4-carboxylic acid wascollected, washed with water and acetone and dried.

This product was acylated with N-t-butoxycarbonylphenylglycine accordingto the procedure of Example 1 to give the t-butoxycarbonyl derivative ofthe title compound. This material was treated with cold trifluoroaceticacid for 15 minutes and concentrated in vacuo to a residue which waspoured into ether. The solid trifluoroacetate salt was collected,dissolved in water and stirred with ion-exchange resin (Amberlite [R45After filtration, the aqueous solution was lyophilized to give the titlecompound.

EXAMPLE 4 7-Mandelamido-3-(4-methyl-5-oxo-A -1,2,4-triazolin-3-ylthiomethyl)-3-eephem-4-carboxylic acid When7-amino-3-(4-methyl-5-oxo-A -1,2.4-triazolin'3-ylthiomethyl)-3-cephem-4-carboxylic acid (6.87 g. 0.02 mol) wasreacted with O-dichloroacetylmandeloyl chloride (12.02 g, 0.043 mol)according to the procedure of Example 2, the title compound wasobtained.

EXAMPLE 5 7-(oz-Aminophenylacetamido)-3(4ethyl-5-oxo-A1,2,4-triazolin-3-ylthiomethyl )-3-cephem-4-carboxylic acid To asuspension of 7-ACA (21.78 g, 0.08 mol) in water (170 ml) and acetoneml) was added a solution of NaHCO (20.16 g, 0.24 mol) in water (160 ml)followed by 4-ethyl-3-thiono-5-oxoA -l,2,4-triazoline (17.42 g, 0.12mol) and acetone (160 ml). The reaction was refluxed for 4 hours duringwhich time the pH was maintained at ca. 7.2 by adding 3N HCI as needed.The solution was cooled and acidified to pH 3 which precipitated theproduct. The 7-aminocephalosporin nucleus was collected, washed withwater and acetone. and dried.

The 7-aminoccphalosporin nucleus (7.15 g, 0.02 mol) was acylated withN-t-butoxycarbonylphenylglycine (50.3 g, 0.02 mol) according to theprocedure of Example 1 to give the N-protected derivative of the titlecompound. Using the method of Example 3 the protecting group was removedto give the title compound.

EXAMPLE 6 7(a-Amino-p-hydroxyphenylacetamido)-3-(5-oxo-A1,2,4-triazolin-3-ylthiomethyl)-3-cephem-4-carboxylie acid The7-aminocephalosporin nucleus from Example 1 (3.62 g., 0.011 mol) wasacylated with N-tbutoxycarbonyl-p-hydroxyphenylglycine (2.67 g, 0.01mol) according to the procedure of Example 1. The N- protected productwas chromatographed on silica gel using :l0:3 chloroform: methanol:formic acid ad eluent. The pure solid was treated with coldtritluoroacetic acid for 15 minutes and then was concentrated and therssidue was poured into ether. The solid trifluoroacetate salt wascollected. dissolved in water and stirred with ion exchange resin(Amberlite 111-45). The filtered aqueous solution was lyophilized togive the title compound.

EXAMPLE 7 7-Mandelamido-3-(5-thiono-A -1,3,4-thiadiazolin-2-ylthiomethyl)-3-cephem-4-carboxylic acid To a suspension of 7-ACA (20.6g. 0.075 mol) and 1,3,4-thiadiazolidine-2,5-dithione in water ml) andacetone (75 ml) was added a solution of NaH- CO (24.2 g) in water (150m1). Ether was added to control the foaming and was then distilled offwhen the EXAMPLE 8 7-( a-Aminophenylacetamido)-3-( l-ethyl-5-oxo-A1,2,4-triazolin-3-ylthiomethyl)-3-cephem-4-carboxylic acid To a stirredsolution of 7-ACA (14.9 g, 0.055 mol) in a mixture of water (I ml) andacetone (55 ml) is added NaHCO (12.27 g, 0.146 mol). The solution iswarmed to 50 and a suspension of l-ethyl-l,2,4-triazolidin-S-one-3-thione (ll.9 g, 0.082 mol) in acetone (75 ml) wasadded slowly. The solution is adjusted to pH 7.5-8.0 and refluxed for3.5 hours. The reaction is cooled and the solution adjusted to pH 3.5.The 7- aminocephalosporin nucleus is collected, washed with water anddried.

The 7-aminocephalosporin nucleus is acylated according to the procedureof Example 1 with N-tbutoxycarbonyl-phenylglycine to give the titlecompound.

. EXAMPLE 9 7-Mandelamido-3-( l-ethyl-S-oxo-N-l ,2,4-triazolin-3-ylthiomethyl)-3-cephem-4-carboxylic acid Acylation of the7-aminocephalosporin nucleus from Example 8 withO-dichloroacetylmandeloyl chloride according to the procedure of Example2 gives the title compound.

EXAMPLE 10 EXAMPLE ll When the 7-aminocephalosporins of Examples 7 and10 are acylated with N-t-butoxycarbonylphenylglycine according to theprocedure of Example 1, the following products are obtained:

7-(a Aminophenylacetamido)-3-( 5-thiono-A -I ,3,4-

thiadiazolin-Z-ylthiomethyl)-3-cephem-4- carboxylic acid7(a-Aminophenylacetamido)-3-( l-methyl-5-oxo- A 1,2,4-triazolin-3-ylthiomethyl )-3-cephem-4- carboxylic acid7-(a-Aminophenylacetamido)-3-(5-oxo-A -l ,3,4-

thiadiazolin-Z-ylthiomethyl)-3-cephem-4- carboxylic acid7-(a-Aminophenylacetamido)-3-(5-thiono-A -l ,2,4-triazolin-3-ylthiomethyl)-3-cephem-4-carboxylic acid 7-(a-Aminophenylacetamido )-3-( 4-.methyl-5- thi0no-A -l,2,4-triazolin-3-ylthiomethyl )-3- cephem-4-carboxylic acid 7-(a-Aminophenylacetamido )-3- 4-ethyl-5-thiono- A -l,2.4-triazolin-3-ylthiomethyl )-3-cephem-4- carboxylic acid EXAMPLE l2Acylation of the 7-aminocephalosporins of Examples 5 and 10 withO-dichloroacetylmandeloyl chloride according to the procedure of Example2 gives the following products:

7-Mandelamido-3-(4-ethyl-5-oxo-A l ,2,4-triazolin-3-ylthiomethyl)-3-cephem-4-carboxylic acid 7-Mandelamido-3-(l-methyl-5-oxo-A -l .2,4-

triazolin-3-ylthiomethyl)-3-cephem-4-carboxylic acid7-Mandelamido-3-(5-oxo-A l .3.4-thiadiazolin-2-ylthiomethyl)-3-cephem-4-carboxylic acid 7-Mandelamido-3-(fi-thiono-A -l.2.-l-triazolin-3- ylthiomethyl)-3-cephem-4-carboxylic acid7-Mandelamido-3-(4-methyl-5-thiono-A -l 2,4-

triaZolin-3-ylthiomethyl)-3-cephem-4-carboxylic acid7-Mandelamido-3-(4-ethyl-5-thiono-A -1,2,4-

triazolin-3-ylthiomethyl)-3-cephem-4-carboxylic acid EXAMPLE 13 The7-aminocephalosporins of Examples 3,5,7,8, and 10 are acylated withN-t-butoxycarbonyl-p-hydroxyphenyl-glycine according to the procedure ofExample 6 to give the following compounds:

7-(a-Amino-p-hydroxyphenylacetamido)-3-(4- methyl-5-oxo-A l.2,4-triazolin-3-ylthiomethyl)-3- cephem-4-carboxylic acid7-(a-Amino-p-hydroxyphenylacetamido)-3-(4-ethyl- 5-OX0-A -l,2,4-triazolin-3-ylthiomethyl)-3- cephem-4-carboxylic acid7-(a-Amino-p-hydroxyphenylacetamido)-3-(5- thiono-A-1.3,4-thiadiazolin-Z-ylthiomethyl)-3- cephem-4-carhoxylic acid7-(a-Amino-p-hydroxyphenylacctamido)-3-( l-eth \'l- 5-oxo-A -l,2.4-tria7.olin-3-ylthiomcthyl-3-cepheni- 4-carboxylic acid7-(a-Amino-p-hydroxyphenylacetamido)-3-( lmethyl-5-oxo-A -l,2,4-triazolin-3-ylthiomethyl )-3- cephem-4-carboxylic acid7-(a-Amino-p-hydroxyphenylacetamido)-3-(5-oxo- A 1,2,4-triazolin-3-ylthiomethyl)-3-cephem-4- carboxylic acid7-(a-Amino-p-hydroxyphenylacetamido)-3-(5- thiono-A -l,2.4-triazolin-3-ylthiomethyl)-3- cephem-4-carboxylic acid7-(a-Amino-p-hydroxyphenylacetamido)-3-(4- methyl-5-thion0-A -l,2,4-triazolin-3- ylthiomethyl)-3-cephem-4-carboxylic acid7-(a-Amino-p-hydroxyphenylacetamido)-3-(4-ethyl- 5-thiono-A-l,2.4-triazolin-3-y|thiomethyl)-3- cephem-4-carboxylic acid EXAMPLE 14A solution of p-hydroxymandelic acid (3.0 g, 0.018 mol) andN-trimethylsilylacetamide (5.31 g, 0.042 mol) in dry THF (60 ml) andtriethylamine (3 ml) is refluxed in a nitrogen atmosphere for 2 hours,cooled to l and then treated with isobutyl chloroformate andl,2,4-triazolidin-5-one-3-thione as in Example 1. The reaction solutionis concentrated to a turbid aqueous mixture which is treated with 3%NaHCO until a clear solution is obtained. Water is added and the aqueoussolution is washed with ether. The aqueous layer is cooled, covered withethyl acetate and acidified to pH 1.5 with 6 N HCl. Phases are separatedand the aqueous layer is reextracted with fresh ethyl acetate. Thecombined extracts are dried and concentrated to give7-(p-hydroxymandelamido )-3-( 5-oxo-A -l ,2,4-triazolin-3-ylthiomethyl)-3-cephem-4-carboxylic acid.

When any of the 7-aminocephalosporins in Examples 3,5,7,8, and 10 areacylated vwith p-hydroxymandelic acid according to the above procedurethe analogous products are obtained.

EXAMPLE When the N-t-butoxycarbonyl p-methoxyphenylglycine,o-methoxyphenylglycine,

derivative of m-methoxyphenylglycine, or p-methylthiophenylglycine issubstituted for N-t-butoxy-carbonylphenylglycine in the procedure ofExample 1 the corresponding 7-(a-amino-substitutedphenylacetamido)-3-(S-oxo- A -l,2,4-triazolin-3-ylthiomethyl)-3-cephem-4- carboxylic acid is obtained.

EXAMPLE 16 EXAMPLE 17 An equilmolar amount ofN-t-butoxycarbonyl-phydroxymethylphenylglycine, N-hydroxysuccinimide,and dicyclohexylcarbodiimide in dry THF is stirred at 0 for 7 hours. Thereaction is filtered and the filtrate is evaporated to give theactivated ester.

To a cooled solution of 7-amino-3-(5-oxo-A -l,2,4-triazolin-3-ylthiomethyl)-3-cephcm-4-carboxylic acid (7.57 g, 0.023 mol)in pyridine (120 ml) containing triethylamine (5.5 ml) is added theactivated ester (8.70 g, 0.023 mol). The reaction is stirred at roomtemperature for 5 hours and poured into water. The aqueous solution wasadjusted to pH 2 and the t-butoxycarbonyl derivative is collected.Treatment with trifluoroacetic acid as in Example 1 gives7-(a-amino-phydroxymethylphenylacetamido)-3-( 5-oxo-A -l ,2,4-triazolin-3-ylthiomethyl)-3 cephem-4-carboxylic. acid.

Acylation of the other 7-aminocephalosporins of Examples 3, 5, 7, 8 and10 with p-hydroxymethylphenylglycine by the above procedure gives thecorresponding products 1 pound EXAMPLE 18 CHCONH Y N A o ca s 2g OOHwhere X is H, CH OH SR, or OR; Y is NH or OH; A is O or S; Z is NR; and

R is hydrogen or C -C alkyl or a nontoxic pharmaceutically acceptablesalt thereof.

2. A compound as claimed in claim 1 wherein X is hydrogen.

3. A compound as claimed in claim 1 where X is phydroxy.

4. A compound as claimed in claim 2 where Z is NR and A is O.

5. A compound as claimed in claim 4 being the compound7-(a-aminophenylacetamido)-3-(5-oxo-A l,2,4-triazolin-3-ylthiomethyl)-3-cephem-4-carboxylic acid.

6. A compound as claimed in claim 4 being the compound7-(a-aminophenylacetamido)-3-(4-methyl-5- oxo-A -l,2,4-triazolin-3-ylthiomethyl)-3-cephem-4- carboxylic acid.

7. A compound as claimed in claim 4 being the compound7-(a-aminophenylacetamido)-3-(4-ethyl-5-oxo- A -l,2,4-triazolin-3-ylthiomethyl)-3-cephem-4- carboxylic acid.

8. A compound as claimed in claim 4 being the com- 7-mandelamido-3-(5-oxo-A l ,2,4-triazolin3- ylthiomethyl)-3-cephem-4-carboxylic acid.

9. A compound as claimed in claim 4 being the compound7-mandelamido-3-(4-methyl-5-oxo-A l ,2,4-triazolin-3-ylthiomethyl)-3-cephem-4-carboxylic acid.

10. A compound as claimed in claim 3 being the compound7-(a-amino-p-hydroxyphenylacetamido)-3- (5-oxo-A -l,2,4-triazolin-3-ylthiomethyl)-3-cephem4- carboxylic acid.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION.

PATENT NO. 1 3,868,369

DATED 1 February 25, 1975 INVENTOR(S) 1 David A. Berges It is certifiedthat error appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

Column 6, line 35, change --50.3- to '5.03"

Column 6, line 51, change --ad-- to "as" Signed and sealed this 6th dayof May 1975.

(SEAL) Attest C MARSHALL DANN RUTH C. MASON Commissioner of PatentsAttesting Officer and Trademarks

1. A COMPOUND OF THE FORMULA
 2. A compound as claimed in claim 1 whereinX is hydrogen.
 3. A compound as claimed in claim 1 where X is p-hydroxy.4. A compound as claimed in claim 2 where Z is NR and A is O.
 5. Acompound as claimed in claim 4 being the compound 7-( Alpha-aminophenylacetamido)-3-(5-oxo- Delta2-1,2,4-triazolin-3-ylthiomethyl)-3-cephem-4-carboxylic acid.
 6. Acompound as claimed in claim 4 being the compound 7-( Alpha-aminophenylacetamido)-3-(4-methyl-5-oxo- Delta2-1,2,4-triazolin-3-ylthiomethyl)-3-cephem-4-carboxylic acid.
 7. Acompound as claimed in claim 4 being the compound 7-( Alpha-aminophenylacetamido)-3-(4-ethyl-5-oxo- Delta2-1,2,4-triazolin-3-ylthiomethyl)-3-cephem-4-carboxylic acid.
 8. Acompound as claimed in claim 4 being the compound7-mandelamido-3-(5-oxo- Delta2-1,2,4-triazolin-3-ylthiomethyl)-3-cephem-4-carboxylic acid.
 9. Acompound as claimed in claim 4 being the compound7-mandelamido-3-(4-methyl-5-oxo- Delta2-1,2,4-triazolin-3-ylthiomethyl)-3-cephem-4-carboxylic acid.
 10. Acompound as claimed in claim 3 being the compound 7-( Alpha-amino-p-hydroxyphenylacetamido)-3-(5-oxo- Delta2-1,2,4-triazolin-3-ylthiomethyl)-3-cephem-4-carboxylic acid.